This revision (NOT-OD-10-032: NIH Announces the Availability of Recovery Act Funds for 3 Competitive Revision Applications (R01, R03, R15, R21, R21/R33, and R37) through the NIH Basic Behavioral 4 and Social Science Opportunity Network (OppNet)) will add ancillary measures of brain structure to a parent 5 study that tests the effect of an 8 month exercise training intervention on cognition and brain function in 6 overweight elementary school children. Children in the parent study are randomly assigned to either a) 40 7 min/d aerobic exercise, or b) an attention control (placebo) condition, to isolate the effects of exercise. The 8 parent study collects data on academic achievement, physiology, behavior, and cognition and its underlying 9 brain activity (assessed using functional magnetic resonance imaging: fMRI) at baseline and post-intervention. 0 Detailed information on the impact of exercise on children's brains will provide information that may be critical 1 to persuade policy makers and educators of the importance of vigorous exercise for brain health and 2 development. This area of research is particularly important due to the increasing rate of inactivity, overweight 3 and their sequelae among children, which impact minority and disadvantaged populations disproportionately. 4 Long Term Goals: The goals of the research program are to test whether exercise benefits children's 5 cognition and achievement, and to test changes in brain activity and structure which underlie those benefits. 6 Specific Aims: The specific aims of the revision are to study brain structure, and specifically to elucidate 7 complex global patterns of brain architecture that may differ between groups after the exercise intervention. 8 Methods: Quantification of brain structure (grey and white matter, and cortical folding) can be optimized 9 with the collection of 3 complementary forms of MRI data. Using sophisticated post-processing strategies, the 0 goal is to integrate the data to create a structured representation of the cortex and then to identify connections 1 between structures based on the brain's resting oscillation pattern. The resulting data provide an excellent 2 solution for the challenging problems of combining data across individual brains and of being able to compare 3 structure and function across groups of subjects. It also allows for brain structure variables (cortical thickness, 4 regional volume, cortical folding, and fiber tract integrity) to be characterized both within and between subjects. 5 These novel approaches have not been applied to an exercise intervention before and will provide important 6 information about the impact of exercise on brain structure. 7 This line of research may have important implications for cognitive development trajectories in children 8 that may affect their long-term achievement. This research program aims to provide evidence to strengthen the 9 basis for policy decisions relating to children's health and education during a childhood obesity epidemic. 0 1 PUBLIC HEALTH RELEVANCE: This research focuses on overweight, sedentary children whose health, cognition, and academic performance are therefore at risk, and who may be particularly responsive to exercise interventions. This study will determine whether regular exercise per se (i.e. compared to attention control, or placebo, condition) affects children's brain structure, and will provide insight into neural mechanisms underlying the benefits of exercise on cognition and achievement. Provision of comprehensive evidence for the benefits of exercise on children's brain health may reduce barriers to vigorous physical activity programs during a childhood obesity epidemic by persuading policymakers, schools and communities that time spent in physical activity enhances, rather than detracts from, learning.